The concept of biological control is no new idea in ecology – people have been transporting living things to control other living things since the late 18th century. The most famous examples seem to be the big failures, where biocontrols become invasive themselves – such as mongooses introduced to Hawaii to control rats but that instead decimated populations of native birds.
Geneticists at the University of Queensland have now successfully applied the biocontrol concept to the ecology of a disease – dengue fever, to be precise. The researchers have cultured a strain of the Wolbachia bacteria that cuts the lifespan of mosquitoes in half — enough time to prevent the dengue virus within them to mature. The result is that even when infected young mosquitoes bite onto human flesh, the human gets away dengue-free.
The bacteria don’t prevent the mosquitoes from breeding, so introducing the Wolbachia into wild mosquito populations won’t wipe them out. Because only the longest-living insects harbor the mature, virulent dengue, the researchers also think that the bacteria is “safe”: the disease probably won’t be able to evolve a shorter life cycle itself. But, of course, this remains to be seen in the wild.
Just goes to remind us that ecology is as important in the guts of some of the smallest animals on the planet as it is across continents.